For example, in a manufacturing process of industrial products, a container storage facility is used to temporarily store containers that accommodate materials, intermediate products, or the like while waiting for a process or the like to be performed. For example, if an item contained in a container is a semiconductor substrate, a reticle substrate, or the like, a container storage facility that is configured to be able to supply a cleaning gas into the stored containers is used in order to avoid contamination of the surface of the substrates while being stored.
As an example, WO 2015/194255A (Patent Document 1) discloses a container storage facility that includes a storage rack (rack 7) that has a plurality of storage sections (storage shelves 7A), and gas supply devices (purge devices 30) for supplying a cleaning gas to the respective storage sections. In the container storage facility in Patent Document 1, the gas supply devices are divided into a plurality of groups (group 1, group 2, . . . group M), and are configured so that each group supplies cleaning gas via branch-type supply pipe (main pipe 412 and supply pipes 33).
In Patent Document 1, it was intended that, when containers (storage containers F) are stored in a plurality of storage sections in the respective groups, the containers are simply stored in order from a storage section that is closer to a gas source (cleaning gas source 47) (paragraphs 0035 to 0038, paragraphs 0049 to 0052, FIG. 5 etc.). However, research by the inventors has revealed that how smoothly the cleaning gas supplied through the supply pipe flows is not always uniform throughout the entire area of the supply pipes, and differs depending on the position in the supply pipe. For this reason, the flow rate of the cleaning gas from one supply pipe is not necessarily uniform in all storage sections that belong to the same group, and differs depending on the position of the storage section relative to the piping route of the supply pipe.
At this time, if a container is first stored in a storage section in which the flow rate of the supplied cleaning gas is relatively low, the cleaning gas is more likely to flow into a storage section in which no container is stored and the flow rate of the supplied cleaning gas is relatively high, and the cleaning gas is less likely to flow into the actually stored container. The same also applies to storage of the second and subsequent containers. Thus, depending on the order in which the containers are stored in a plurality of storage sections in the same group, the flow rate of the cleaning gas supplied to the respective storage sections via the supply pipe may vary.